This invention relates to chromatography immunoassay devices in which chromatography strips are used. More particularly, the invention relates to a chromatography immunoassay device in which one or more chromatography strips are located on a substrate, each of the chromatography strips is sealed between the substrate and a seal film that entirely covers the chromatography strips, and the seal film and/or substrate is possessed of a film containing a dehumidifying agent and/or a film containing an oxygen absorbing agent.
Chromatography immunoassay devices, in which chromatography strips are used, are devices which immunologically detect or measure the presence or quantity of substances to be assayed that are contained in samples, the device having at least a sample adding means and a detecting means. In some cases the chromatography strip also has a labeling means, and such a device is well known and broadly used, as disclosed for example in JP-A-61-145459 (the term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined, published Japanese patent applicationxe2x80x9d), JP-A-1-63865 and JP-W-1-503174 (the term xe2x80x9cJP-Wxe2x80x9d as used herein means an xe2x80x9cunexamined, published Japanese international patent applicationxe2x80x9d), all incorporated herein by reference.
Each chromatography strip must be protected by appropriate means, such as packaging, in order to prevent antibodies and like reagents in the chromatography strip from degeneration caused by oxygen, moisture and the like, and to protect the strip itself from pollution caused by touching, or from deformation and the like. Protection by packaging or the like means is effected generally by sticking or putting one or a plurality of chromatography strips on a substrate, putting the resulting preparation into a protective case and then sealing the case in a bag. Alternatively, each chromatography strip is sealed with a laminate film as disclosed in WO 94/24563, incorporated herein by reference. When packed in a bag, the chromatography strip is sealed together with a dehumidifying agent in order to minimize moisture absorption by the chromatography strip.
In the conventional chromatography immunoassay device, however, each chromatography strip requires a protective case, a dehumidifying agent and a package where one chromatography strip is sealed, thus costing much for packaging. In a case in which a plurality of chromatography strips are stuck on a substrate, all of the chromatography strips are packed in a single bag together with a necessary amount of a dehumidifying agent and sealed with a packaging material which is substantially water impermeable. Though this method can reduce the cost required for the packaging material and dehumidifying agent, unsealing the bag to use a first chromatography strip causes exposure of other chromatography strips to the air, or moisture and oxygen, thus posing a problem of causing their deterioration. Thus, it is necessary to take special protective and storage measures, because the stored chromatography strips become useless when they are not properly protected and stored. Case WO 94/24563, incorporated herein by reference, uses chromatography strips which can be isolated from the air, but no additional measures are provided to protect the chromatography strips from moisture and oxygen.
The present invention resolves the aforementioned problems seen with the prior art chromatography immunoassay devices in terms of their mode and packaging, thereby providing a chromatography immunoassay device which is easier to use, can be isolated from moisture and/or oxygen more effectively, enabling storage over a longer period of time, and that is able to be produced at a lower cost.
A chromatography immunoassay device has been developed which can be used more easily, is protected from moisture and/or oxygen more effectively and has low production cost. This invention is a chromatography immunoassay device in which one or more chromatography strips are located on a substrate, each of the chromatography strips is sealed between the substrate and a seal film that entirely covers the chromatography strips, and the seal film and/or substrate possesses a film containing a dehumidifying agent and/or a film containing an oxygen absorbing agent.
Accordingly, the gist of the present invention resides in a chromatography immunoassay device in which: (1) one or more chromatography strips, having at least a sample adding means and a detecting means, are located at certain intervals on a substrate which is comprised of one plate, with or without a strip support, (2) a seal film that entirely covers the chromatography strips is located on the aforementioned chromatography strip with or without a protective laminate, (3) each of the chromatography strips is sealed by adhering the aforementioned seal film closely to a portion of the substrate around each chromatography strip, (4) the aforementioned adhesion of the seal film to the substrate is effected in such a way that the seal film can be peeled easily from the substrate, at least at the sample-adding area, (5) with regard to the seal film and substrate, (i) either the seal film or substrate has both a film containing a dehumidifying agent and a film containing an oxygen absorbing agent, (ii) the seal film has either a film containing a dehumidifying agent or a film containing an oxygen absorbing agent, and the substrate has the other film, (iii) either the seal film or substrate has either the film containing a dehumidifying agent or the film containing an oxygen absorbing agent, and the other has both the film containing a dehumidifying agent and the film containing an oxygen absorbing agent, (iv) both the seal film and substrate each contain both the film containing a dehumidifying agent and the film containing an oxygen absorbing agent, (v) the seal film and the substrate both contain the same film which is either the film containing a dehumidifying agent or the film containing an oxygen absorbing agent, or (vi) either the seal film or substrate contains either the film containing a dehumidifying agent or the film containing an oxygen absorbing agent, and (6) the seal film and substrate are substantially water impermeable, at least at the portion where the seal film is not adhered closely to the substrate when the seal film and/or substrate has the film containing a dehumidifying agent, and the seal film and substrate are substantially oxygen impermeable, at least at the portion where the seal film is not adhered closely to the substrate when the seal film and/or substrate has the film containing an oxygen absorbing agent.
A chromatography immunoassay device is described which can be used easily, is protected from moisture and/or oxygen and has low production cost. This invention is a chromatography immunoassay device in which one or more chromatography strips are stuck on a substrate made of a single plate, each of the chromatography strips is sealed by closely adhering a substrate portion surrounding each chromatography strip to a seal film located on the aforementioned chromatography strip, and the seal film and/or substrate is possessed of a film containing a dehumidifying agent and/or a film containing an oxygen absorbing agent. Since chromatography strips are isolated from moisture and/or oxygen by the seal film and substrate, they can be stored for a more prolonged period of time. Also, even in the case of a device in which a plurality of chromatography strips are stuck on a substrate, when one chromatography strip is used the remaining chromatography strips are not exposed to air, unlike similar types of conventional devices currently in use. Also, a chromatography strip in the invention herein can be separated from other strips, together with the substrate, without exposing it to air before or after its use. In addition, the chromatography immunoassay device of the present invention does not require labor for packaging which is needed to produce the chromatography strips of the prior art. Thus the strips described herein can be produced at a lower cost.
In a chromatography strip, at least a sample adding means and a detecting means are arranged on a chromatography carrier. A sample solution having a possibility of containing a substance to be assayed moves through the chromatography carrier by capillary action when added to the sample adding means, and a labeled substance which is contained in a labeling means arranged on the chromatography strip in advance, or a labeled substance which is added together with the sample solution to the chromatography strip, is accumulated in the detecting means in direct or inverse proportion to the presence or quantity of the substance to be assayed in the sample solution, effected by a immunological reaction, so that the presence or quantity of the substance to be assayed in the sample solution can be found by measuring the presence or quantity of the thus accumulated labeled substance. Various types of chromatography strips are known, and all of these known chromatography strips, including those which will be described later, can be used in the present invention. The term xe2x80x9cchromatography immunoassay devicexe2x80x9d as used herein means a chromatography strip which is produced in such a way that it can be used in an immunoassay and is able to be stored and transported.
The following describes a typical example of the chromatography strip. When a labeling means is present, a sample adding means may be located either at the same place where the labeling means is present or at an upstream position to the labeling means (hereinafter, direction of the movement of a sample solution caused by capillary action is called xe2x80x9cdownstreamxe2x80x9d and the opposite direction is called xe2x80x9cupstreamxe2x80x9d), with upstream to the labeling means generally preferred. When a sample solution, having a possibility of containing a substance to be assayed, is introduced into the sample adding means, the sample solution moves through the chromatography carrier in the downstream direction together with the substance to be assayed effected by capillary action. Typically, the substance to be assayed is a compound which binds in a specific fashion to a trapping substance fixed to the detecting means, or it is a compound which binds in a specific fashion to a conjugate that binds specifically to the trapping substance. For example, the substance to be assayed is an antibody when the trapping substance is an antigen or the conjugate contains an antigen, and the substance to be assayed is an antigen when the trapping substance is an antibody or the conjugate contains an antibody.
When the sample adding means is located at an upstream position to a labeling means (a case in which a labeling means is present), the labeling means may be arranged adjacent to the sample adding means or on a position disconnected from the sample adding means. Typically, a labeled substance which binds specifically to a substance to be assayed or binds specifically to a trapping substance in competition with the substance to be assayed is arranged in the labeling means.
When a labeling means is not present, a labeled substance may be added to the sample adding means together with a sample solution, but addition of the labeled substance can be effected by various means for example by adding it to a certain position outside the chromatography strip binding site after addition of the sample solution.
The label may be a radioactive isotope, an enzyme or a colored substance such as gold colloid or the like. These labels are also well known.
Since the labeled substance is arranged in such a manner that it moves by the capillary action of a sample solution, the labeled substance moves in the downstream direction when the sample solution is added to the sample adding means.
The detecting means is generally located at a downstream position from the labeling means and at a certain distance from the labeling means. In the detecting means, a trapping substance which binds only to a substance to be assayed or a conjugate in a specific fashion, or binds specifically to each of the substance to be assayed and a labeled substance, is fixed to the chromatography carrier. Consequently, in one embodiment the substance to be assayed (sometimes linked to a labeled substance), moved by the capillary action of the sample solution, binds to the trapping substance or to a conjugate which in turn binds to the trapping substance. The labeled substance binds to the thus bound substance to be assayed, thereby effecting accumulation of the labeled substance in the detecting means in response to the presence or quantity of the substance to be assayed. Alternatively, the labeled substance and the substance to be assayed, moved by capillary action, bind competitively to the trapping substance or to a conjugate which in turns binds to the trapping substance, thereby effecting accumulation of the labeled substance in inverse proportion to the quantity of the substance to be assayed.
There is a case in which a certain labeled substance binds to both a trapping substance (or a conjugate which in turn binds to a trapping substance) and a substance to be assayed, but not simultaneously and, in that case, the substance to be assayed firstly binds to the labeled substance and the remaining labeled substance which did not bind to the substance to be assayed binds to the trapping substance. In consequence, the presence or quantity of the substance to be assayed can be analyzed by measuring the labeled substance accumulated in the detecting means.
As occasion demands, various substances are located upstream of the detecting means. For example, a conjugate may be so located in a movable manner. A Conjugate is a complex of a compound which binds specifically to a substance to be assayed or a labeled substance and another compound which specifically binds to a trapping substance, and it binds to both the substance to be assayed and the trapping substance or the labeled substance and the trapping substance in a specific manner. Examples of the combination of a compound which specifically binds to a trapping substance and the corresponding trapping substance include biotin and avidin (either could be the trapping substance), an antibody and its corresponding antigen (both having no relation to a sample to be assayed) and the like.
In some cases, one or more additional detecting means may be arranged downstream of the first detecting means. Also, downstream of the detecting means there may be a further extension of the chromatography carrier so that a sample solution can be discharged completely or the carrier may be equipped with a material for use in the absorption of the sample solution.
The chromatography carrier is a carrier of the sample adding means, labeling means and detecting means, which connects these means in such a manner that a sample solution can move by capillary action. A number of materials have been proposed as chromatography carriers, and any of these materials can be used as the chromatography carrier of the present invention. For example, cellulose, nitrocellulose, cellulose acetate and the like are used most frequently as chromatography carriers.
Thus, the presence or quantity of a substance to be assayed in a sample solution can be found by measuring the presence or quantity of a labeled substance accumulated in the detecting means. In one instance, this may be accomplished visually.
As occasion demands, the chromatography strip may be adhered to a strip support in such a manner that one of its sides contacts the strip support (hereinafter, the side in contact with the strip support is called the xe2x80x9crear facexe2x80x9d of the chromatography strip). The strip support is used mainly to prevent movement of the sample adding means, labeling means and the like. Sticking of the chromatography strip onto the strip support must be done in such a way that the capillary action of a sample solution in the chromatography carrier is not disturbed so that the sensitivity of detection of a substance to be assayed is not reduced. In some cases, the strip support may be used in such a way that a portion of the sample adding means is not covered.
Also, as occasion demands, a protective laminate may be stuck on the opposite side of the strip support-adhered side of the chromatography strip (hereinafter, this side, or the side opposite to the substrate-adhered side, is called the xe2x80x9cfront facexe2x80x9d of the chromatography strip ). The protective laminate is used mainly to ensure adhesion of the sample adding means and labeling means and to prevent staining and other flaws from occurring to the chromatography strip when used. At least a portion of the protective laminate, where it covers the detecting means, must be transparent, and the sample adding portion of the sample adding means must not be covered by the protective laminate. Sticking of the chromatography strip to the protective laminate must be done in such a way that the capillary action of a sample solution in the chromatography carrier is not disturbed, or so that the sensitivity of detection of a substance to be assayed is not reduced.
Polyethylene terephthalate (to be referred to as xe2x80x9cPETxe2x80x9d hereinafter) is used most frequently as the strip support and protective laminate; polypropylene (to be referred to as xe2x80x9cPPxe2x80x9d hereinafter), polyvinyl chloride and the like may also be used.
Adhesion of the chromatography strip to the strip support or protective laminate, or adhesion of the strip support to the substrate which will be described later, may be effected by the use of a rubber, acrylic or vinyl ether polymer adhesive agent.
One or more chromatography strips may be located on a strip substrate with or without the strip support. The term xe2x80x9cto locatexe2x80x9d as used herein means that the chromatography strips are simply put on the substrate or, in another instance, they are stuck on the strip support, when it is present, or on the substrate, when the strip support is not present. The term xe2x80x9cto stickxe2x80x9d as used herein means that either the whole surface or just a portion of the chromatography strip is adhered to the substrate. In any case, sticking of the chromatography strip is effective if it does not easily separate from the strip support or substrate during its production or when it is used. In some cases, the substrate may be stuck with paste so that it can be peeled easily from the chromatography strip or strip support.
When the strip support is not used, the substrate may also have the function of the strip support.
When a plurality of chromatography strips are located on the substrate, it is desirable, from the production point of view, to make the downstream and upstream ends of each chromatography strip uniform so that they are parallel. These chromatography strips are located on the substrate and are-a certain distance apart.
The substrate is comprised of a single plate and is stuck on the strip support, when it is present, or on the rear face of the chromatography strip.
The chromatography strip is sealed by closely adhering a seal film, which will be described later, to the substrate at the peripheral area of each chromatography strip located on the substrate, namely the space between chromatography strips when a plurality of the strips are located on the substrate.
The seal film is a sheet of film which can cover the entire portion of the chromatography strip and is located on the chromatography strip with or without the protective laminate.
If the substrate is closely adhered to the seal film by hot sealing, the inner side of the substrate (the side where the chromatography strip is present) and inner side of the seal film (the side where the chromatography strip is present) must be able to be hot-sealed, i.e. they must contain materials that are hot-sealable. Examples of such hot-sealable materials for the seal film and substrate include a combination of a film having polyethylene (to be referred to as xe2x80x9cPExe2x80x9d hereinafter) or PP on its inner side and a film whose inner side is coated with a corresponding hot melt adhesive or a combination of a film having PE on its inner side and a film having a PP-PE copolymer film on its inner side.
If the seal film is stuck on the substrate with paste, this may be effected by a combination of an optional seal film and a substrate having on its inner side a rubber, acrylic or vinyl ether polymer adhesive agent.
Close adhesion of the seal film and substrate should be made in such a manner that the substrate and seal film can be peeled off easily when used, at least at the position of the sample adding means. In order to effect easy peeling of the substrate and seal film and to keep proper sealing performance, a peeling strength of 1.5 to 2.0 kg weight per 15 mm width is desirable.
With regard to the seal film and substrate, (i) either the seal film or substrate has both a film containing a dehumidifying agent and a film containing an oxygen absorbing agent, (ii) the seal film has either a film containing a dehumidifying agent or a film containing an oxygen absorbing agent, and the substrate has the other film, (iii) either the seal film or substrate has either the film containing a dehumidifying agent or the film containing an oxygen absorbing agent, and the other has both the film containing a dehumidifying agent and the film containing an oxygen absorbing agent, (iv) both the seal film and substrate each have both the film containing a dehumidifying agent and the film containing an oxygen absorbing agent, (v) the seal film and the substrate both contain the same film which is either the film containing a dehumidifying agent or the film containing an oxygen absorbing agent, or (vi) either the seal film or substrate contains either the film containing a dehumidifying agent or the film containing an oxygen absorbing agent. When the seal film and/or substrate has the film containing a dehumidifying agent, the seal film and substrate are substantially water impermeable, at least at the portion where the seal film is not adhered closely to the substrate, and when the seal film and/or substrate has the film containing an oxygen absorbing agent, the seal film and substrate are substantially oxygen impermeable, at least at the portion where the seal film is not adhered closely to the substrate.
When the seal film has the film containing a dehumidifying agent, the seal film has a water impermeable layer on its outer side. Also, when the seal film has the film containing an oxygen absorbing agent, the seal film has an oxygen impermeable layer on its outer side. In the same manner, when the substrate has the film containing a dehumidifying agent, the substrate has a water impermeable layer on its outer side, and when the substrate has the film containing an oxygen absorbing agent, the substrate has an oxygen impermeable layer on its outer side. In many cases, the outermost side of the seal film is prepared in such a way that printing can be made thereon.
When the seal film and/or substrate does not have the film containing a dehumidifying agent and the film containing an oxygen absorbing agent, the seal film and/or substrate may be a single layer film or a multiple layer film which is obtained by an optional combination of an oxygen impermeable film, a water impermeable film, a film suited for hot sealing, an outermost PET film and the like.
When the substrate and seal film both have no oxygen absorbing agent-containing film, the substrate and seal film are not necessarily oxygen impermeable, and the substrate and seal film are not necessarily water impermeable when the substrate and seal film both have no dehumidifying agent-containing film. That is, it is not necessary to use a dehumidifying agent-containing film or water impermeable seal film and substrate when the chromatography strip is not degenerated by moisture, or to use an oxygen absorbing agent-containing film or oxygen impermeable seal film and substrate when the chromatography strip is not degenerated by oxygen.
The dehumidifying agent-containing film can be prepared by kneading a thermoplastic high molecular weight resin, preferably a polyolefin and more preferably one selected from low density polyethylene, linear low density polyethylene, ethylene-vinyloxide copolymers, ethylene acrylic acid copolymers, ethylene methacrylic acid copolymers, ethylene acrylic ester copolymers and ionomers based on acrylic and methacrylic acid copolymers, with an appropriate amount of calcium chloride, silica gel, molecular sieve, silicon dioxide, alumina, zeolite magnesium sulfate, gypsum and the like which are used as desiccating agents. Examples of the dehumidifying agent-containing films include those disclosed in Japanese Patent Publication 08-026348 (26348/96) incorporated herein by reference, xe2x80x9cMoisture Guardxe2x80x9d (manufactured by Toyo Seikan) and xe2x80x9cHiseat-Dry Filmxe2x80x9d (manufactured by Marutani Kakoki). A particularly preferred dehumidifying agent-containing film is 110 micrometer and composed of about 10 micrometer low density PE (LDPE), about 90 micrometer desiccant layer, containing varying amounts of a high molecular weight resin, such as LDPE, and a desiccating agent such as zeolite, molecular sieve and the like, and about 10 micrometer LDPE. Suitable dehumidifying agent-containing films preferably have a layer with a desiccating agent content between about 0.1 and 50% by weight, perferably between 10% and 50%. An overall desiccant content of between about 8 and 50 grams per meter squared is especially preferred. It is preferred to use a desiccant with an average particle size between about 5 and 70 microns to prepare the layer containing the desiccating agent.
The oxygen absorbing agent-containing film can be prepared by kneading a thermoplastic high molecular weight resin with an appropriate amount of active iron oxide, pyrogallol and the like oxygen absorbing agents. An example of an oxygen absorbing agent-containing film is xe2x80x9cOxy Guardxe2x80x9d (manufactured by Toyo Seikan).
In some cases, the seal film is a film which has both a dehumidifying agent and an oxygen absorbing agent. Such a type of seal film can be called herein either a dehumidifying agent-containing film or an oxygen absorbing agent-containing film. In the same manner, the substrate may be a film which has both a dehumidifying agent and an oxygen absorbing agent. Such a type of substrate can be called herein either a dehumidifying agent-containing film or an oxygen absorbing agent-containing film.
Illustrative examples of the substrates which are substantially water impermeable include PE of 300 micrometer or more, PP of 300 micrometer or more, a multiple layer film consisting of, from the inner side, [PE or PP] of 300 micrometer or more and polyvinylidene chloride (to be referred to as xe2x80x9cPVDCxe2x80x9d hereinafter) of about 15 micrometer, and a multiple layer film consisting of, from the inner side, [PE or PP] of about 70 micrometer, PET of about 125 micrometer and PVDC of about 15 micrometer. Illustrative examples of substrates which are substantially water impermeable and contain a dehumidifying agent-containing film include xe2x80x9cMoisture Guardxe2x80x9d of 300 micrometer and a multiple layer film consisting of, from the inner side , xe2x80x9cMoisture Guardxe2x80x9d of about 110 micrometer, PET of about 125 micrometer and PVDC of about 15 micrometer. Illustrative examples of the substrates which are substantially oxygen impermeable include a multiple layer film consisting of, from the inner side, [PE or PP] of about 150 micrometer or more, polyvinyl alcohol saponificate of about 15 micrometer and [PE or PP] of 150 micrometer or more. The above examples are all transparent.
Illustrative examples of substrates which are substantially water and oxygen impermeable include a multiple layer film consisting of, from the inner side, [PE or PP] of 150 micrometer or more, PVDC of about 30 micrometer and [PE or PP] of 50 micrometer or more. Illustrative examples of substrates which are substantially water and oxygen impermeable and opaque include a multiple layer film consisting of, from the inner side, [PE or PP] of 200 micrometer or more, aluminum foil (to be referred to as xe2x80x9cAlxe2x80x9d hereinafter) of about 7 micrometer and PET of about 15 micrometer; a multiple layer film consisting of, from the inner side, [PE or PP] of 70 micrometer, PET of about 125 micrometer, Al of about 7 micrometer and PET of 12 micrometer; and a multiple layer film consisting of, from the inner side, [PE or PP] of about 70 micrometer, polystyrene of about 125 micrometer, Al of about 7 micrometer and PET of about 12 micrometer.
A preferred substrate consists of, from the inner side, about 30 micrometer of a layer that facilitates the removal of the seat film and is composed of a blend of PE and PP, about 188 micrometer white PET (for color contrast), about 7 micrometer Al (as an oxygen and moisture barrier) and about 12 micrometer PET. A particularly preferred substrate consists of, from the inner side, about 30 micrometer of a layer that facilitates the removal of the seal film and is composed of a blend of PE and PP, about 50 micrometer white PET, about 7 micrometer Al, and about 188 micrometer PET.
A substrate which is substantially water and oxygen impermeable and contains a dehumidifying agent- and/or oxygen absorbing agent-containing film can be obtained by replacing the inner film of the aforementioned multiple layer film which is substantially water and oxygen impermeable with xe2x80x9cMoisture Guardxe2x80x9d of 110 to 250 micrometer and/or xe2x80x9cOxy Guardxe2x80x9d of 110 to 250 micrometer.
As occasion demands, pastes of rubber, acrylic or a vinyl ether polymer system may be applied to the sides, particularly inner side, of the substrate, In that case, release paper or release film is laminated on the paste-applied side until used. Paper, PET, PP or the like may be used as the release paper or release film with no particular limitation.
As illustrative examples of the seal film, those which are substantially water impermeable include a multiple layer film consisting of, from the inner side, [PE or PP] of about 70 micrometer and PET of about 12 micrometer. Those which are substantially oxygen impermeable include a multiple layer film consisting of, from the inner side, [PE or PP] of about 70 micrometer, polyvinyl alcohol saponificate of about 15 micrometer, PP of about 12 micrometer and PET of about 12 micrometer. Those which are substantially water and oxygen impermeable include a multiple layer film consisting of, from the inner side, [PE or PP] of about 70 micrometer, PVDC of about 30 micrometer and PET of about 12 micrometer. All of the above examples are transparent.
Illustrative examples of seal films which are substantially water impermeable and contain a dehumidifying agent-containing film include a multiple layer film consisting of, from the inner side, xe2x80x9cMoisture Guardxe2x80x9d of 110 micrometer and PET of about 12 micrometer (transparent) and a particularly preferred multiple layer film consisting of, from the inner side, xe2x80x9cMoisture Guardxe2x80x9d of about 110 micrometer, Al of about 7 micrometer and PET of about 12 micrometer (opaque). An illustrative example of a seal film which is substantially oxygen impermeable and contains an oxygen absorbing agent-containing film is a multiple layer film consisting of, from the inner side, xe2x80x9cOxy Guardxe2x80x9d of 110 micrometer, Al of 7 micrometer and PET of 12 micrometer (opaque). An illustrative example of a seal film which is substantially water and oxygen impermeable and contains dehumidifying agent-containing film and oxygen absorbing agent-containing film is a multiple layer film consisting of, from the inner side, xe2x80x9cMoisture Guardxe2x80x9d of 110 micrometer, xe2x80x9cOxy Guardxe2x80x9d of 110 micrometer, Al of about 7 micrometer and PET of 12 micrometer (opaque).
The multiple layer film can be produced by sticking its composing films together with an appropriate adhesive agent or by laminating parts of its composing films by means of co-extrusion and then, if necessary, by sticking the remaining composing materials together with an appropriate adhesive agent.
The chromatography immunoassay device can be produced by firstly preparing the aforementioned chromatography strips and, if necessary using a strip support and/or a protective laminate in the aforementioned manner, or preparing chromatography strips and simultaneously sticking a sample adding means and the like together, sealing the chromatography strip through tight adhesion of the aforementioned substrate to the seal film.
The chromatography immunoassay device of the present invention is used in the following manner. Only a single chromatography strip to be used is cut off, together with the substrate. The seal film, or at least a portion covering the sample adding means, is peeled off and a sample solution is added to the thus exposed sample adding means. In the case of a certain shape of the seal film, it may be necessary to peel off the whole portion of the seal film which covers the chromatography strip. When a plurality of chromatography strips are located on the substrate and a chromatography strip is used without first cutting it off, it is generally cut off after it is used. In some cases, the device may be used by separating the substrate from the strip support.
The present invention is further described with reference to the drawings. FIG. 1 is a schematic illustration showing an example of the chromatography immunoassay device of the present invention. In the drawing, a is a plan view, b is a sectional view and c is another sectional view. FIG. 2 is a schematic illustration showing an example of the chromatography strip. FIG. 3 is a schematic illustration showing another example of the chromatography immunoassay device of the present invention. In these drawings, 1 indicates a chromatography strip, 2 indicates a substrate, 3 indicates a seal film, 4 indicates a chromatography carrier, 5 indicates a sample adding means, 6 indicates a labeling means, 7 indicates a detecting means, 8 indicates a strip support, 9 indicates a protective laminate, 10 indicates a perforation and 11 (slant lines) indicates closely adhered portions of the substrate and seal film.
The chromatography strip 1 is located on the substrate 2, and, together with a dehumidifying agent- and/or oxygen absorbing agent-containing film, the chromatography strip 1 is sealed and isolated from the air by closely adhering the seal film 3 to the chromatography strip peripheral area 11 of the substrate 2 (FIG. 1).
When a comb type substrate is used as shown in FIG. 3, the sample adding means of each chromatography strip is completely isolated so that there is no possible danger of a sample solution flowing into an adjacent chromatography strip by mistake when the sample is added.
The chromatography strip 1 is constructed by arranging the sample adding means 5, labeling means 6 and detecting means 7 on the chromatography carrier 4 (FIG. 2). As occasion demands, the chromatography strip is supported or protected by the strip support 8 and protective laminate 9.
The perforation 10 is optionally arranged when required, in order to effect easy cut off of a single chromatography strip from the chromatography immunoassay device when a plurality of chromatography strips are located on the substrate. The perforation 10 may be used in such a manner that a single chromatography strip can be cut off or several chromatography strips can be cut off simultaneously.